numerous: Donegal-Derry and Ulster generally. Ir. Mac an Chrosáin, crosán was a jester or satirist in medieval Ireland. Two septs of this name: one in Ulster, the other in the Midlands. See also Cross. SI.

fairly numerous: Tyrone-Donegal & Ulster generally; Kildare and scattered in the south. Ir. Mac an Chrosáin, crosán, a rhymer, entertainer. There were families in Tyrone and Kildare - the latter now usually Crosby. SGG.